Ten years ago I stood on a remote, nondescript rock outcropping in northern Idaho, and in my mind’s eye I conjured up a vision of some men who had preceded me there by more than a century and a half. They were Meriwether Lewis, William Clark, and the Corps of Discovery; their arrival at Sherman Peak was the climax of their crossing of the LoIo Trail, the Indians’ old buffalo road through the northern Rockies—and in some ways it was the climax of their transcontinental journey.

Lewis and Clark were such extraordinary leaders that much of their great exploration seemed remarkably uneventful. The outcome was in doubt only during those excruciating days on the LoIo. Winter was coming on, game was scarce, the terrain almost impassable to man or beast; the men were exhausted, their feet were freezing, they were on starving times. They ate their horses, a raven, a coyote.

It was a near thing, but when they stumbled up onto Sherman Peak, they could see open prairie to the west, and they knew that their ordeal was over. Soon after, they met a band of Nez Perce Indians. It was the first contact between white men and that estimable tribe, and the amicable Nez Perce received the explorers warmly, provided them with buffalo meat, salmon and camas root, and then guided them down the Snake and the Columbia to the Pacific, thus making possible the completion of a journey that would irrevocably shape the future. Although Lewis and Clark didn’t find the Northwest Passage they were looking for, they would draw the nation west, and nothing would ever be the same again.